In the faulty point analysis of a semiconductor sample having a circuit formed on a semiconductor surface, it is important to identify a faulty point part. On the other hand, it is difficult to identify a faulty point part due to microfabrication of a device in recent years. As a result, it takes an enormous amount of time in the faulty point analysis. Therefore, at present, an optical beam induced resistance change (OBIRCH), an electron beam (EB) tester and other analyzers have been used for this type of faulty point analysis.
Among others, in the field of the faulty point analysis of a wire, a technology that irradiates the semiconductor samples with the charged particle beam typified by an electron beam, brings a probe into contact with samples, analyzes a current absorbed by the wire or secondary signals (for example, secondary electrons or reflection electrons) emitted from the semiconductor samples and images them has attracted attention. A distribution image of a signal (absorption current signal) obtained on the basis of a current (absorption current) absorbed by the wire is referred to as an electron beam absorbed current image (EBAC).
JP-A-2008-203075 (Patent Literature 1) discloses an absorption current detection apparatus that irradiates a wire pattern on a sample surface with a charged particle beam, brings two probes a and b into contact with the wire pattern, and measures an absorption current flowing into the probe a and b. In Patent Literature 1, it is characterized that the apparatus is configured to apply an absorption current flowing into the probe a and b to a current/voltage converter through an input resistor having a predetermined resistance value for adjusting an output voltage.
On the other hand, JP-A-2009-252854 (Patent Literature 2) discloses a technology that easily identifies a faulty point part, by varying a temperature of a sample when absorption current images are generated and acquiring a difference image between the absorption current images generated at each temperature, even if a signal displacement between a faulty portion and a normal portion is small.